The invention relates generally to rigging hardware, such as for lifting and towing, and more particularly, to an anti-fouling device placed on a thimble or a cable loop connected to a D-ring, shackle, clevis, or similar structure.
Generally, operators of boats, tractors, trucks, or other equipment often lift or tow large objects. The coupling between the vehicle and the object may be formed by a chain, a rope, a bar, a wire cable, or some other assembly for keeping the object connected to the vehicle while in motion. For example, in one exemplary towing operation, tractors may be coupled to one another to pull one machine away from or out of difficult terrain, such as in a field. The tractors often include a D-ring, shackle, clevis, or other device to facilitate coupling the chain/rope/bar/wire to the tractor. For example, a cable may include a loop at the end which extends around the d-ring/shackle/clevis. A thimble or U-shaped bolt is often installed inside the loop to reduce wear on the chain/rope/wire and to strengthen the connection.
Under certain conditions, such as turning on an uneven surface, the thimble or cable may twist to where an eye of the thimble or cable enters an end of the shackle or d-ring and bind to the end of a shackle or D-ring. For instance, on articulated agricultural tractors, turning while driving over a mound of soil can create slack in the cable. Once slack is created, the cable can twist around the D-ring. If the D-ring bolt is in contact with the thimble when the tractor straightens, the thimble and bolt can bind in a fouled position. This fouling can cause the towed object to be off center or angled, which may increase stress on the D-ring, the thimble, the cable, or a combination thereof. When this occurs, individuals who drive tractors may spend additional time to correct the binding, either with additional driving or physical removal.